Most small car designs earned poor ratings in side-impact crashtests recently conducted by the Insurance Institute for HighwaySafety. The test represented what happens when a passenger vehicleis struck in the side by a pickup truck or SUV.

“These side-impact results are similar to the results in 1997,when the institute first rated small cars in the frontal offsetcrash test,” said Adrian Lund, chief operating officer for theIIHS. “Back then, no small car earned a good frontal crash testrating. Now, almost every small car earns a good rating in thefrontal test. As manufacturers redesign their vehicles, we expectthat small cars will get better in the side-impact test too.”

Only the Chevrolet Cobalt and Toyota Corolla, both equipped withoptional side air bags with head protection, performed well enoughto earn the institute's second highest rating of acceptable.Without the optional air bags, the Cobalt and Corolla were ratedpoor for side-impact protection.

“With the curtain air bags, the heads of the dummies in thefront and rear seats of the Cobalt and Corolla were cushioned, andhead injury measures were low,” said Lund. “Head injuries are afactor in many deaths in real-world side-impact crashes, and sideair bags designed to protect the head make a big difference.”

In the Cobalt, forces on the driver dummy's torso indicated thepossibility of rib fractures or internal organ injuries. In theCorolla, there was the possibility of a fractured pelvis.Protection for the rear passenger was good in both cars.

Another 12 small cars earned poor ratings: Dodge Neon, FordFocus, Hyundai Elantra, Kia Spectra, Mazda 3, Mitsubishi Lancer,Nissan Sentra, Saturn ION (tested with and without side air bags),Suzuki Forenza, Suzuki Aerio, and Volkswagen New Beetle. Three moresmall cars will be tested in side impacts later this year. The MiniCooper and Subaru Impreza will have new design features that areintended to improve side impact protection. The Honda Civic will bea completely redesigned model.

In the side-impact test, a moving deformable barrier strikes thedriver side of a passenger vehicle at 31 mph. The barrier weighs3,300 pounds and has a front end shaped to simulate the front endof a typical pickup or SUV. Each side-struck vehicle contains twoinstrumented dummies the size of a small woman, one positioned inthe driver seat and one in the rear seat behind the driver.

The worst performer was the Neon, according to Lund. “This caris a disaster,” he said. “The structure is poor, and both dummies'heads were hit by the barrier during the crash test. High forceswere recorded on the head, torso, and pelvis of the driver dummy.If this had been a real driver in a real crash, it's likely that itwould not have been survivable.”

Vehicles need good structure, as well as side air bags, Lundnoted. Four of the vehicles that earned poor ratings (Elantra,Forenza, New Beetle, and Spectra) were equipped with standard sideair bags with head protection. These cars were rated good oracceptable for head injury measures recorded on the driver dummies.The Saturn ION with optional side air bags also earned anacceptable rating for driver head injury. However, the structuresof all of these vehicles allowed too much intrusion during thetest. Forces recorded on the driver dummies' torsos and pelvicareas were high.

“Side air bags can protect the head, but if the vehiclestructure doesn't hold up well, serious injuries to other bodyregions still can occur,” Lund said. “With better structures alongwith the side air bags, the performances of these vehicles wouldimprove.”

Side air bags with head protection are reducing deaths by about45 percent among drivers of cars struck on the driver's side,according to IIHS research. Before the availability ofhead-protecting air bags, virtually nothing prevented people'sheads from being struck by intruding vehicles or rigid objects,such as trees or poles. Side air bags that protect the chest andabdomen, but not the head, also have reduced deaths by about 10percent. Well designed doors with appropriate padding areadditional protection for the chest and abdomen.